Method

1. FOR THE BISCUIT

Preheat the oven to 160c. Melt the butter and blitz in a food processor with the biscuits, sugar and egg white. Tip the mixture into one large or six small tart case(s) and spread out to cover the base and sides of the tin evenly. Chill in the fridge for 10 minutes before baking for 10 minutes then leaving to cool.

2. FOR THE FILLING

Whisk the egg yolks in a bowl with the condensed milk. Add the zest and juice of the limes and mix well. Pour into the biscuit base and bake at 160c for 10-15 minutes until the filling has just set, but hasn't changed colour. Remove from the oven and leave to cool.

3. FOR THE ICING

Put the sugar and water into a saucepan and place over a high heat. Stir until the sugar has dissolved and bring the mixture up to 118c (soft ball stage). Meanwhile whisk the egg whites in a mixer until firm peaks are achieved. Reduce the speed and gradually pour in the sugar syrup. Turn the speed back up and continue whisking until the mixture has cooled down to room temp (approximately 5 minutes).
Spread or pipe the merinugue on top of the curd filling and brown with a blowtorch.

Chef's tip

«Use Florida key limes if you can get hold of them to make the truly authentic version. You'll need approximately twice as many as regular limes. »